ISOTACHOPHORETIC SEPARATION OF RARE-EARTH IONS .1. SEPARATION BEHAVIOR OF YTTRIUM AND 14 LANTHANIDE IONS FORMING COMPLEXES WITH TARTARIC ACID AND ALPHA-HYDROXYISOBUTYRIC ACID

A leading electrolyte for the isotachophoretic separation of yttrium i on from lanthanide ions was developed, consisting of 20 mM ammonia sol ution containing 0.5 mM tartaric acid and 8 mM alpha-hydroxyisobutyric acid (HIB) as complex-forming agents. The pH of the solution was adju sted to 4.8 by adding acetic acid. Using the electrolyte system develo ped, the separation behaviour of fifteen rare earth ions was studied i n comparison with a simple HIB system. It was revealed that the additi on of tartaric acid lowered the separability of adjacent pairs of medi um and heavy lanthanide ions to two-thirds of that of HIB system, inst ead of the successful separation of Dy and Y. The electrolyte system d eveloped was applied to the separation of a rare earth ore sample cont aining Y as one of the major components.